Formation and Propagation of Matter Wave Soliton Trains

TL;DR

This paper reports the experimental creation and observation of stable matter wave soliton trains in a Bose-Einstein condensate of lithium-7 atoms confined in a quasi-one-dimensional optical trap, demonstrating controlled formation and propagation of solitons.

Contribution

It demonstrates the formation of stable bright soliton trains in a Bose-Einstein condensate by tuning interactions, advancing understanding of nonlinear wave phenomena in quantum gases.

Findings

Stable soliton trains observed in a quasi-1D optical trap.

Solitons propagate without spreading over many cycles.

Repulsive interactions between solitons inferred from their motion.

Abstract

Attraction between atoms in a Bose-Einstein-Condensate renders the condensate unstable to collapse. Confinement in an atom trap, however, can stabilize the condensate for a limited number of atoms, as was observed with 7Li, but beyond this number, the condensate collapses. Attractive condensates constrained to one-dimensional motion are predicted to form stable solitons for which the attractive interactions exactly compensate for the wave packet dispersion. Here we report the formation or bright solitons of 7Li atoms created in a quasi-1D optical trap. The solitons are created from a stable Bose-Einstein condensate by magnetically tuning the interactions from repulsive to attractive. We observe a soliton train, containing many solitons. The solitons are set in motion by offsetting the optical potential and are observed to propagate in the potential for many oscillatory cycles without spreading. Repulsive interactions between neighboring solitons are inferred from their motion.